John Pendleton Kennedy, born in Baltimore 25 October 1795, graduated from Baltimore College in 1812 and fought in the Battles of Bladensburg and North Point in the War of 1812. Although admitted to the bar in 1816. he was much more interested in literature and politics than law. He published "Swallow Barn" in 1832 and "Horseshoe Robinson" in 1835 to win a permanent place of respect in the history of American fiction. He was an active Whig winning a seat in the Maryland House of Delegates in 1820. In 1838 he succeeded Isaac McKim in the House of Representatives but was defeated in his bid for reelection in November of that year. He was re-elected to Congress in 1840 and 1842; but, because of his strong opposition to the annexation of Texas, he was defeated in 1844. His influence in Congress was largely responsible for the appropriation of $30,000 to test Samuel Morse's telegraph.

President Fillmore appointed Kennedy Secretary of the Navy in July 1852. While he held the office, four important naval expeditions were organized including that which sent Commodore Matthew C. Perry to Japan.

Kennedy retired from public life in March 1853 when President Fillmore left office, but he retained an active interest in politics and forcefully supported the Union. At the end of the Civil War he advocated amnesty for the South. He died at Newport, R.I., 18 August 1870.

John P. Kennedy, the former wooden sailing ship Sea Nymph, was purchased at New York in 1853 to participate in an expendition to the North Pacific Ocean to explore for commercial and naval purposes waters in the area of the Bering Straits and the China Seas, which were "frequented by American whaleships and trading vessels in their routes between the United States and China." The expedition, under Comdr. Cadwalader Ringgold, besides supply ship John P. Kennedy, consisted of sloop-of-war Vincennes (flagship), brig Porpoise, schooner Fenimore Cooper, and bark John Hancock.

John P. Kennedy departed New York 21 June 1853 and arrived Cape of Good Hope 10 September. She departed Cape of Good Hope 9 November with the expedition and arrived Batavia, Java, the day after Christmas. She took active part in surveying operations in Indonesian waters until putting in at Singapore 4 April 1854 en route to Hong Kong where she arrived 25 May for repairs. In August the high cost of placing her in good condition prompted Lt. John Rodgers, who had succeeded Commander Ring-gold in command, to turn John P. Kennedy over to the East Indies Squadron to become a guard ship at the American Factory, Canton, China. The ship stood out of Hong Kong 20 August and arrived at her new station 2 days later.

After a violent storm 23 July 1855, John P. Kennedy assisted American ship Isabella Catana in getting afloat; and she aided survivors of a Chinese man-of-war after the ship caught fire and blew up 6 September. She departed Canton 20 October in tow of Powhatan, arriving Hong Kong the next day. She decommissioned there 31 October and was sold in November 1855.